This program continues our present interdisciplinary approach to effect solutions to new molecular identification and quantification problems in the chemical, biochemical, biomedical and clinical research areas of direct relevance to human health. The program will make available to investigators from a wide spectrum of biomedical research disciplines state-of-the-art techniques in high performance computerized double focusing mass spectrometry and the expertise necessary to apply successfully such unique instrumentation to their research problems. We will continue to foster developments in mass spectrometry and computer technology which will facilitate solutions for: 1) structure determinations of polar, polyfunctional, labile biological substances in the microgram sample range and below; 2) studies of the qualitative and quantitative composition of complex mixtures isolated from biological sources with emphasis on: field desorption, fast atom/ion bombardment, collision cell work, linked scanning, extended mass range, higher mass resolutions, glass capillary gas chromatography/high resolution mass spectrometry, and elementatl composition chromatgraphy. Specific areas of clinical importance include: Steroid endocrinology and hypertension, drug metabolism and conjugation, the molecular basis of toxicity, mutagenicity and carcinogenesis, and gentic diseases. Studies in organic, natural products and biochemistry will also continue.